Impact-actuated projectile fuze

ABSTRACT

A projectile housing. A body of pyrotechnic material in the housing. A fuze container fixed to the base end of the housing. A burning fuze material in the fuze container, the container fabricated of a material that looses its structural integrity in response to the heat of the fuze flame front, whereby upon impact of the projectile that container separates exposing the burning fuze to the body of pyrotechnic material.

United States Patent Inventors Appl. No. Filed Patented AssigneelMPACT-ACTUATED PROJECTILE FUZE 21 Claims, 3 Drawing Figs.

US. Cl 102/73, 102/58, 102/7611, 102/85 Int. Cl F42: 1/10, F42c 9/00Field of Search 102/58, 38, 70, 73, 75, 85. 76

[56] References Cited UNITED STATES PATENTS 2,627.160 2/1953 MacDonald102/70 X 3.345.945 10/1967 Quinlan et a1. 102/38 3,353,488 11/1967Stadler eta] 102/73 Primary Examiner-Samuel W. Engle Attorney-Allen J.Jafl'e ABSTRACT: A projectile housing. A body of pyrotechnic material inthe housing. A fuze container fixed to the base end of the housing. Aburning fuze material in the fuze container, the container fabricated ofa material that looses its structural integrity in response to the heatof the fuze flame front, whereby upon impact of the projectile thatcontainer separates exposing the burning fuze to the body of pyrotechnicmaterial.

PATENTEUUEB nan 3,525,152

sum 2 or 2 INVENTOR RICHARD E. REINNAGEL CLAYTON J. SCHNE!DER,JR.

ATTOR NEY IMPACT-ACTUATED PROJECTILE FUZE BACKGROUND OF THE INVENTIONThe present invention relates to fuzes, and more particularly to thosewhich are armed upon firing and actuated upon impact.

Fuzes have been used which prevent immediately actuation of the maincharge by the provision of a fixed delay period or by the provision forimpact actuation or both. The systems utilizing impact actuation usuallyincorporate some form of mechanical latching or detaining means which isreleased upon impact of the projectile. Such mechanical structuresuffers from several serious drawbacks. Mechanical systems are usuallycostly, large and may be subject to premature actuation due to roughhandling.

SUMMARY OF THE INVENTION The foregoing as well as other disadvantages ofprior devices are overcome according to the principles of the presentinvention which provides an impact actuated fuze which is inexpensive,safe and compact.

Basically, the present invention provides a pyrotechnic delay materialpacked in a tube or container which is rigidly affixed to the base endof the projectile. Upon suitable ignition of the delay material, themechanical properties of the tube are effectively destroyed, thuspermitting the burning pyrotechnic to travel in a direction which makescontact with the main charge upon impact.

According to one aspect of the invention, suitable for stabilizedprojectiles, the burning pyrotechnic delay material travels forwardtoward the nose end of the projectile upon impact.

According to a second aspect of the invention, suitable fornonstabilized projectiles such as grenades, the burning pyrotechnicdelay material may travel radially outward through slots in a supportingmember.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of thepresent invention reference should now be had to the following detaileddescription of the same taken in conjunction with the accompanyingdrawings, wherein:

FIG. I is a longitudinal sectional view of a projectile embodying theprinciples of the present invention,

FIG. 2 is a fragmentary sectional view of a second embodiment, and

FIG. 3 is a schematic plan representation ofa third embodimCI'II.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawingsand, more particularly, to FIG. I, the projectile housing is generallydepicted by the numeral I and is defined by a generally cylindralcentral section 12 to which is suitably affixed a cup-shaped forward endor ogive l4 and a base end plug, 16. Forward end 14 has a conventionalvent opening 15 therethrough. The housing may be fabricated of anysuitable material such as an aluminum alloy or steel. The base end plugI6 has an inwardly stepped ledge I8 terminating in a central opening 20.Passing through opening and extending into the projectile housing is atubular insulating and supporting sleeve 22, which may be fabricated ofany suitable material such as plastic. Sleeve 22 is affixed to the plugI6 at the ledge I8 by means of an integral flange 24.

A cylindrical, tubular fuze container 26 is received in sleeve 22 and issuitably affixed thereto, as by cement or the like, adjacent flange 24.In this manner the fuze container is fixed to the base end of theprojectile housing.

A body of fusing material 28 is located within container 26. Thismaterial might typically comprise a slag and/or gas producingpyrotechnic such as 3 percent boron and 97 percent barium chromatemixture. A first fire mix 30 ofa suitable pressed priming material suchas red lead and silicon closes the base end of container 26 and passesthrough an opening 32 in flange 24 to the exterior of the projectilehousing for ignition in the conventional manner. A similar output mix 34closes the opposite or forward end of container 26.

A main charge 36 substantially fills the interior of the housing [0except for a central bore 38 in which is located the fusing material 28,its container 26 and supporting sleeve 22. The main charge mightcomprise any suitable type of burning pyrotechnic such as red smoke, forexample.

The fuze container 26 is fabricated of a material which is sufficientlyweakened by the traveling flame front in the fusing material 28 suchthat upon impact of the forward end of the projectile the forwardportions ofthe container separates from the rearward portion thereof.Various materials exhibiting such a weakness, may be chosen. Forexample, a thin-walled aluminum tube having a thickness of about 0.012inches becomes molten adjacent the flame front. Alternatively. aphenolic or plastic tube, would become pyrolized adjacent the flamefront. In either case, the flame front causes the material of thecontainer adjacent thereto to loose its structural integrity wherebyupon impact separation occurs.

The operation of the device according to the present invention should beapparent from the foregoing description. Thus, when the projectile isfired by conventional means (not illus trated) the first fire mix 30receives ignition (from propellant in a cartridge case, for example) andburns through the opening 32 into the fusing material 28 which isthereby ignited generating a flame front which travels towards theforward end of the projectile. The heat of the flame front is sufficientto melt, pyrolize or otherwise weaken the structural integrity of thefuse container. Upon impact with a target, the container 26 separates atthe weakened spot and the unburned portion of the fusing materialtogether with the flame front and considerable quantities of slag fromthe burned portion of the fus ing material travel beyond the sleeve 22into the main charge 36 and ignite the same. In the event that aninsufficient impact fails to part the container or if impact does notoccur in a specified time, say 6 seconds, the fusing material continuesto burn until it ignites the output mix 34 which sprays flame and slaginto main charge to ignite the same. The insulating sleeve 22 preventsthe heat of combustion of the burning delay mix 28 from igniting themain charge 36 prior to impact or before the end of the specified timeperiod.

Although the foregoing description related. by way ofexample, to theignition of a pyrotechnic material by means of a traveling ignitionsource, it is obvious that a pin or stab could be placed on the forwardend of the fuze which would function to initiate a primer at the forwardend of the projectile. In this manner a detonation output can beobtained.

The forms of the invention shown in FIGS. 2 and 3 relate to projectilesthat are not stabilized in flight such as hand-thrown grenades or thelike. Here there is no guarantee that the projectile will impact in anose-forward position.

The FIG. 2 embodiment is similar to the previously described FIG. Iembodiment, except that the insulating and supporting sleeve, designatedas 22; has a plurality of longitudinally extending slots 23'. Uponimpact at any orientation, the molten or pyrolized portions of fusecontainer 26 together with the slag and flame from the fusing material28 splashes through the slots 23' to trigger the ignition of the maincharge.

Alternatively as shown in FIG. 3, a plurality of fuzes, each similar tothe fuze elements 22, 26, 28, 30 and 34 of the FIG. I embodiment, couldbe joined together at hub I00, which structure would then be located ina spherical projectile housing embedded within a main charge (notillustrated). In this manner one of the fuzes of the set would besubject to set-forward forces regardless of the angle of impact of thedevice. The fuzes are shown in a common plane for ease in presentationonly. It is preferable that various planes be occupied by separatefuzes.

Although various embodiments of the present invention have beendescribed by way of example, other forms thereof will be obvious tothose skilled in the art.

We claim:

1. A projectile, comprising:

a. a housing having a forward end and a base end.

b. a main charge of ignitable material in said housing,

c. a container fixed to said housing,

d. a fusing material located within said container and normallyseparated from contact with said main charge,

e. means for igniting said fusing material prior to impact of theprojectile thereby generating a traveling flame front, and

f. said container being fabricated of a material which is sufficientlyweakened by said flame front such that upon impact of said housing aportion of said container separates from the remainder thereof whereuponthe separated portion and the fusing material comes into contact withsaid main charge.

2. The projectile according to claim I, wherein said container is fixedto said base end of said housing.

3. The projectile according to claim I, wherein said container issubstantially tubular.

4. The projectile according to claim 3, further comprising a tubularinsulating and support sleeve fixed to said housing and in surroundingspaced relation to said container.

5. The projectile according to claim 4, wherein said sleeve contains aplurality of longitudinally extending slots.

6. The projectile according to claim I, further comprising additionalcontainers each mutually interconnected with said first mentionedcontainer by means ofa central hub.

7. The projectile according to claim I, wherein:

g. said main charge substantially fills said housing, and has athroughbore extending therethrough and wherein,

h. said container is substantially tubular and located within saidthroughbore.

8. The projectile according to claim 7 wherein said container is affixedto the base end of said housing.

9. The projectile according to claim 8, further comprising a sleeveextending from said base end into said throughbore in surroundingrelation to said container.

10. The projectile according to claim 9, wherein said sleeve has aplurality of longitudinal slots.

II. A projectile comprising:

a. a housing having a forward end and a base end,

b. a main charge of ignitable material located in said housc. acontainer in said housing fixed to said base end,

d. a fusing material located within said container and normallyseparated from said main charge,

e. means for igniting said fusing material prior to impact of theprojectile to generate a flame front which travels in a direction fromsaid base end to said forward end of said housing, and

f. said container being fabricated of a material which is sufficientlyweakened by said flame front such that upon impact of said forward endof said housing the forward portion of said container separates from thebase portion thereof and travels into said main charge.

12. The apparatus according to claim ll, wherein;

g. said container is substantially tubular and there is furtherprovided;

h. a sleeve surrounding said container, and

i. first fire and output mixes located respectively at the base end andforward end of said container.

13. The apparatus according to claim [2, wherein said container islocated in a throughbore in said main charge.

14. A projectile fuze, comprising;

a. a container b. a body of fusing material located in said container,c. means for igniting said fusing material prior to impact of theprojectile for generating a traveling flame front, and d. said containerbeing fabricated of a material which is sufficiently weakened by saidflame from such tat upon impact a portion of said container separatesfrom the remainder thereof.

15. The fuze according to claim 14, further comprising:

e. insulating means in surrounding relation to said container.

16. The fuze according to claim 14, further comprising; e. a first firemix at one end of said container, and

f. an output mix at the other end of said container.

17. The fuze according to claim 14, wherein;

e. said container is substantially tubular.

18. The fuze according to claim 17, further comprising;

f. a tubular insulating sleeve in surrounding spaced relation to saidcontainer.

19. The fuze according to claim l8, wherein;

g. said sleeve contains a plurality of longitudinally extending slots.

20. The fuze according to claim 19, further comprising;

h. a first fire mix at one end of said container, and

i. an output mix at the other end ofsaid container.

21. The fuze according to claim l4, further comprising;

e. additional containers, each mutually interconnected with said firstmentioned container by means ofa central hub.

a t e a 4-

1. A projectile, comprising: a. a housing having a forward end and abase end, b. a main charge of ignitable material in said housing, c. acontainer fixed to said housing, d. a fusing material located withinsaid container and normally separated from contact with said maincharge, e. means for igniting said fusing material prior to impact ofthe projectile thereby generating a traveling flame front, and f. saidcontainer being fabricated of a material which is sufficiently weakenedby said flame front such that upon impact of said housing a portion ofsaid container separates from the remainder thereof whereupon theseparated portion and the fusing material comes into contact with saidmain charge.
 2. The projectile according to claim 1, wherein saidcontainer is fixed to said base end of said housing.
 3. The projectileaccording to claim 1, wherein said container is substantially tubular.4. The projectile according to claim 3, further comprising a tubularinsulating and support sleeve fixed to said housing and in surroundingspaced relation to said container.
 5. The projectile according to claim4, wherein said sleeve contains a plurality of longitudinally extendingslots.
 6. The projectile according to claim 1, further comprisingadditional containers each mutually interconnected with said firstmentioned container by means of a central hub.
 7. The projectileaccording to claim 1, wherein: g. said main charge substantially fillssaid housing, and has a throughbore extending therethrough and wherein,h. said container is substantially tubular and located within saidthroughbore.
 8. The projectile according to claim 7 wherein saidcontainer is affixed to the base end of said housing.
 9. The projectileaccording to claim 8, further comprising a sleeve extending from saidbase end into said throughbore in surrounding relation to saidcontainer.
 10. The projectile according to claim 9, wherein said sleevehas a plurality of longitudinal slots.
 11. A projectile comprising: a. ahousing having a forward end and a base end, b. a main charge ofignitable material located in said housing, c. a container in saidhousing fixed to said base end, d. a fusing material located within saidcontainer and normally separated from said main charge, e. means forigniting said fusing material prior to impact of the projectile togenerate a flame front which travels in a direction from said base endto said forward end of said housing, and f. said container beingfabricated of a material which is sufficiently weakened by said flamefront such that upon impact of said forward end of said housing theforward portion of said container separates from the base portionthereof and travels into said main charge.
 12. The apparatus accordingto claim 11, wherein; g. said container is substantially tubular andthere is further provided; h. a sleeve surrounding said container, andi. first fire and output Mixes located respectively at the base end andforward end of said container.
 13. The apparatus according to claim 12,wherein said container is located in a throughbore in said main charge.14. A projectile fuze, comprising; a. a container b. a body of fusingmaterial located in said container, c. means for igniting said fusingmaterial prior to impact of the projectile for generating a travelingflame front, and d. said container being fabricated of a material whichis sufficiently weakened by said flame front such that upon impact aportion of said container separates from the remainder thereof.
 15. Thefuze according to claim 14, further comprising: e. insulating means insurrounding relation to said container.
 16. The fuze according to claim14, further comprising; e. a first fire mix at one end of saidcontainer, and f. an output mix at the other end of said container. 17.The fuze according to claim 14, wherein; e. said container issubstantially tubular.
 18. The fuze according to claim 17, furthercomprising; f. a tubular insulating sleeve in surrounding spacedrelation to said container.
 19. The fuze according to claim 18, wherein;g. said sleeve contains a plurality of longitudinally extending slots.20. The fuze according to claim 19, further comprising; h. a first firemix at one end of said container, and i. an output mix at the other endof said container.
 21. The fuze according to claim 14, furthercomprising; e. additional containers, each mutually interconnected withsaid first mentioned container by means of a central hub.